Some portable electronic devices have built-in cameras. These devices may provide digital viewfinders for user-interaction with the cameras. The digital viewfinders may allow variable image zooming through the use of optical and/or digital magnification. Optical magnification provides better visual quality but introduces complexities in the device's optical train, as optical zooming is achieved by moving physical components (e.g., lenses) along a physical, optical train. Digital magnification avoids these complexities, thereby permitting more efficient device packaging, but may suffer in visual quality.